/* Copyright (C) 2000, 2011, Oracle and/or its affiliates. All rights 
   reserved

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* This file should be included when using heap_database_functions */
/* Author: Michael Widenius */

#ifndef _heap_h
#define _heap_h
#ifdef	__cplusplus
extern "C" {
#endif

#ifndef _my_base_h
#include <my_base.h>
#endif

#include <my_pthread.h>
#include <thr_lock.h>

#include "my_compare.h"
#include "my_tree.h"

    /* defines used by heap-funktions */

#define HP_MAX_LEVELS	4		/* 128^5 records is enough */
#define HP_PTRS_IN_NOD	128

        /* struct used with heap_funktions */

    typedef struct st_heapinfo /* Struct from heap_info */ {
        ulong records; /* Records in database */
        ulong deleted; /* Deleted records in database */
        ulong max_records;
        ulonglong data_length;
        ulonglong index_length;
        uint reclength; /* Length of one record */
        int errkey;
        ulonglong auto_increment;
    } HEAPINFO;

        /* Structs used by heap-database-handler */

    typedef struct st_heap_ptrs {
        uchar * blocks[HP_PTRS_IN_NOD]; /* pointers to HP_PTRS or records */
    } HP_PTRS;

    struct st_level_info {
        /* Number of unused slots in *last_blocks HP_PTRS block (0 for 0th level) */
        uint free_ptrs_in_block;

        /*
          Maximum number of records that can be 'contained' inside of each element
          of last_blocks array. For level 0 - 1, for level 1 - HP_PTRS_IN_NOD, for 
          level 2 - HP_PTRS_IN_NOD^2 and so forth.
         */
        ulong records_under_level;

        /*
          Ptr to last allocated HP_PTRS (or records buffer for level 0) on this 
          level.
         */
        HP_PTRS *last_blocks;
    };

    /*
      Heap table records and hash index entries are stored in HP_BLOCKs.
      HP_BLOCK is used as a 'growable array' of fixed-size records. Size of record
      is recbuffer bytes.
      The internal representation is as follows:
      HP_BLOCK is a hierarchical structure of 'blocks'.
      A block at level 0 is an array records_in_block records. 
      A block at higher level is an HP_PTRS structure with pointers to blocks at 
      lower levels.
      At the highest level there is one top block. It is stored in HP_BLOCK::root.

      See hp_find_block for a description of how record pointer is obtained from 
      its index.
      See hp_get_new_block 
     */

    typedef struct st_heap_block {
        HP_PTRS *root; /* Top-level block */
        struct st_level_info level_info[HP_MAX_LEVELS + 1];
        uint levels; /* number of used levels */
        uint records_in_block; /* Records in one heap-block */
        uint recbuffer; /* Length of one saved record */
        ulong last_allocated; /* number of records there is allocated space for */
    } HP_BLOCK;

    struct st_heap_info; /* For referense */

    typedef struct st_hp_keydef /* Key definition with open */ {
        uint flag; /* HA_NOSAME | HA_NULL_PART_KEY */
        uint keysegs; /* Number of key-segment */
        uint length; /* Length of key (automatic) */
        uint8 algorithm; /* HASH / BTREE */
        HA_KEYSEG *seg;
        HP_BLOCK block; /* Where keys are saved */
        /*
          Number of buckets used in hash table. Used only to provide
          #records estimates for heap key scans.
         */
        ha_rows hash_buckets;
        TREE rb_tree;
        int (*write_key)(struct st_heap_info *info, struct st_hp_keydef *keyinfo,
                const uchar *record, uchar *recpos);
        int (*delete_key)(struct st_heap_info *info, struct st_hp_keydef *keyinfo,
                const uchar *record, uchar *recpos, int flag);
        uint(*get_key_length)(struct st_hp_keydef *keydef, const uchar *key);
    } HP_KEYDEF;

    typedef struct st_heap_share {
        HP_BLOCK block;
        HP_KEYDEF *keydef;
        ulong min_records, max_records; /* Params to open */
        ulonglong data_length, index_length, max_table_size;
        uint key_stat_version; /* version to indicate insert/delete */
        uint records; /* records */
        uint blength; /* records rounded up to 2^n */
        uint deleted; /* Deleted records in database */
        uint reclength; /* Length of one record */
        uint changed;
        uint keys, max_key_length;
        uint currently_disabled_keys; /* saved value from "keys" when disabled */
        uint open_count;
        uchar *del_link; /* Link to next block with del. rec */
        char * name; /* Name of "memory-file" */
        THR_LOCK lock;
        mysql_mutex_t intern_lock; /* Locking for use with _locking */
        my_bool delete_on_close;
        LIST open_list;
        uint auto_key;
        uint auto_key_type; /* real type of the auto key segment */
        ulonglong auto_increment;
    } HP_SHARE;

    struct st_hp_hash_info;

    typedef struct st_heap_info {
        HP_SHARE *s;
        uchar *current_ptr;
        struct st_hp_hash_info *current_hash_ptr;
        ulong current_record, next_block;
        int lastinx, errkey;
        int mode; /* Mode of file (READONLY..) */
        uint opt_flag, update;
        uchar *lastkey; /* Last used key with rkey */
        uchar *recbuf; /* Record buffer for rb-tree keys */
        enum ha_rkey_function last_find_flag;
        TREE_ELEMENT * parents[MAX_TREE_HEIGHT + 1];
        TREE_ELEMENT **last_pos;
        uint lastkey_len;
        my_bool implicit_emptied;
        THR_LOCK_DATA lock;
        LIST open_list;
    } HP_INFO;

    typedef struct st_heap_create_info {
        HP_KEYDEF *keydef;
        ulong max_records;
        ulong min_records;
        uint auto_key; /* keynr [1 - maxkey] for auto key */
        uint auto_key_type;
        uint keys;
        uint reclength;
        ulonglong max_table_size;
        ulonglong auto_increment;
        my_bool with_auto_increment;
        my_bool internal_table;
        /*
          TRUE if heap_create should 'pin' the created share by setting
          open_count to 1. Is only looked at if not internal_table.
         */
        my_bool pin_share;
    } HP_CREATE_INFO;

    /* Prototypes for heap-functions */

    extern HP_INFO *heap_open(const char *name, int mode);
    extern HP_INFO *heap_open_from_share(HP_SHARE *share, int mode);
    extern HP_INFO *heap_open_from_share_and_register(HP_SHARE *share, int mode);
    extern void heap_release_share(HP_SHARE *share, my_bool internal_table);
    extern int heap_close(HP_INFO *info);
    extern int heap_write(HP_INFO *info, const uchar *buff);
    extern int heap_update(HP_INFO *info, const uchar *old, const uchar *newdata);
    extern int heap_rrnd(HP_INFO *info, uchar *buf, uchar *pos);
    extern int heap_scan_init(HP_INFO *info);
    extern int heap_scan(register HP_INFO *info, uchar *record);
    extern int heap_delete(HP_INFO *info, const uchar *buff);
    extern int heap_info(HP_INFO *info, HEAPINFO *x, int flag);
    extern int heap_create(const char *name,
            HP_CREATE_INFO *create_info, HP_SHARE **share,
            my_bool *created_new_share);
    extern int heap_delete_table(const char *name);
    extern void heap_drop_table(HP_INFO *info);
    extern int heap_extra(HP_INFO *info, enum ha_extra_function function);
    extern int heap_reset(HP_INFO *info);
    extern int heap_rename(const char *old_name, const char *new_name);
    extern int heap_panic(enum ha_panic_function flag);
    extern int heap_rsame(HP_INFO *info, uchar *record, int inx);
    extern int heap_rnext(HP_INFO *info, uchar *record);
    extern int heap_rprev(HP_INFO *info, uchar *record);
    extern int heap_rfirst(HP_INFO *info, uchar *record, int inx);
    extern int heap_rlast(HP_INFO *info, uchar *record, int inx);
    extern void heap_clear(HP_INFO *info);
    extern void heap_clear_keys(HP_INFO *info);
    extern int heap_disable_indexes(HP_INFO *info);
    extern int heap_enable_indexes(HP_INFO *info);
    extern int heap_indexes_are_disabled(HP_INFO *info);
    extern void heap_update_auto_increment(HP_INFO *info, const uchar *record);
    ha_rows hp_rb_records_in_range(HP_INFO *info, int inx, key_range *min_key,
            key_range *max_key);
    int hp_panic(enum ha_panic_function flag);
    int heap_rkey(HP_INFO *info, uchar *record, int inx, const uchar *key,
            key_part_map keypart_map, enum ha_rkey_function find_flag);
    extern uchar * heap_find(HP_INFO *info, int inx, const uchar *key);
    extern int heap_check_heap(HP_INFO *info, my_bool print_status);
    extern uchar *heap_position(HP_INFO *info);

    /* The following is for programs that uses the old HEAP interface where
       pointer to rows where a long instead of a (uchar*).
     */

#if defined(WANT_OLD_HEAP_VERSION) || defined(OLD_HEAP_VERSION)
    extern int heap_rrnd_old(HP_INFO *info, uchar *buf, ulong pos);
    extern ulong heap_position_old(HP_INFO *info);
#endif
#ifdef OLD_HEAP_VERSION
    typedef ulong HEAP_PTR;
#define heap_position(A) heap_position_old(A)
#define heap_rrnd(A,B,C) heap_rrnd_old(A,B,C)
#else
    typedef uchar *HEAP_PTR;
#endif

#ifdef	__cplusplus
}
#endif
#endif
